What is wrong with my settings?

I have a problem with my schedule and it is not possible for me to solve it. I have the following setting: One appointment window per week (Monday) from 08:30 to 12:30 o´clock. Each appointment within this window has a duration of 45 minutes.
The booking time should look like this:

08:30 – 9:15 Appointment 1
9:15 – 10:00 Appointment 2
10:00 – 10:45 Appointment 3
10:45 – 11:00 break
11:00 – 11:45 Appointment 4
11:45 – 12:30 Appointment 5
Who can help? What is wrong with my settings?

http://www.inst.uni-giessen.de/career-centre/individuelle_karriereberatung/